/**
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 * 
 * 1. Redistributions of source code must retain the above copyright notice,
 * this list of conditions and the following disclaimer.
 * 
 * 2. The name "Antonio W. Lagnada" must not be used to endorse or promote
 * products derived from this software without prior written permission. For
 * written permission, please contact tony@lagnada.com
 * 
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES,
 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
 * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL ANTONIO W.
 * LAGNADA OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
package org.j2ee.example.ejb.factory;

import java.rmi.RemoteException;
import java.util.HashMap;
import java.util.Map;

import javax.ejb.CreateException;
import javax.ejb.EJBHome;
import javax.naming.InitialContext;
import javax.naming.NamingException;
import javax.rmi.PortableRemoteObject;

/**
 * EJBHomeFactory
 * 
 * @author Antonio Lagnada
 */
public class EJBHomeFactory {

    private static EJBHomeFactory m_factory = null;

    private final static Map<String, Class> JNDI_MAP = new HashMap<String, Class>();
    static {
        JNDI_MAP.put("ejb/AccountManager", AccountManagerHome.class);
    }

    public EJBHomeFactory() {

    }

    public synchronized final static EJBHomeFactory getInstance() {
        if (m_factory == null) {
            m_factory = new EJBHomeFactory();
        }
        return m_factory;
    }

    public static void main(String[] args) {
        // The old way
        try {

            AccountManagerHome remoteHome = (AccountManagerHome) EJBHomeFactory
                    .getInstance().getRemoteHomeTheOldWay("ejb/AccountManager");
            AccountManager mgr = remoteHome.create();
            mgr.doSomething();
        } catch (RemoteException e) {
            e.printStackTrace();
        } catch (CreateException e) {
            e.printStackTrace();
        }

        // Using JDK 1.5 Typesafety
        try {
            AccountManagerHome remoteHome = EJBHomeFactory.getInstance()
                    .getRemoteHome("ejb/AccountManager");
            AccountManager mgr = remoteHome.create();
            mgr.doSomething();
        } catch (RemoteException e) {
            e.printStackTrace();
        } catch (CreateException e) {
            e.printStackTrace();
        }
    }

    @SuppressWarnings("unchecked")
    public <T extends EJBHome> T getRemoteHome(String jndiHomeName)
            throws RemoteException {

        T home = null;

        try {
            InitialContext ctx = new InitialContext();
            Object objRef = ctx.lookup(jndiHomeName);
            Class homeClazz = JNDI_MAP.get(jndiHomeName);
            home = (T) PortableRemoteObject.narrow(objRef, homeClazz);
        } catch (NamingException e) {
            throw (new RemoteException("Failed lookup on jndi [" + jndiHomeName
                    + "]", e));
        }

        return home;
    }

    public EJBHome getRemoteHomeTheOldWay(String jndiHomeName)
            throws RemoteException {

        EJBHome home = null;

        try {
            InitialContext ctx = new InitialContext();
            Object objRef = ctx.lookup(jndiHomeName);
            Class homeClazz = JNDI_MAP.get(jndiHomeName);
            home = (EJBHome) PortableRemoteObject.narrow(objRef, homeClazz);
        } catch (NamingException e) {
            throw (new RemoteException("Failed lookup on jndi [" + jndiHomeName
                    + "]", e));
        }

        return home;
    }
}
